A mass campaign to support an ongoing lawsuit against manufacturers of the defoliant used by US forces during the Vietnam War has gained widespread support in the communist country.

According to official figures impossible to verify, more than 11.5 million people have added their signatures to a campaign launched by the Vietnam Association for Victims of Agent Orange (VAVA), and hundreds of thousands more have shown their support online.

"We received active participation from the people, from pupils to state employees," said VAVA vice president Nguyen Trong Nhan.

"I even think the number of 11.5 million signatures has not reflected the reality. More will turn up," the professor added.

Between 1961 and 1971, the US sprayed tens of millions of litres (gallons) of herbicides over South Vietnam to destroy the vegetation communist VietCong forces used for cover and food. Agent Orange was the most common.

Vietnam says many people's health problems and deformities were caused by the defoliant, which contains toxic dioxins which some say spread through the food chain, causing birth defects.

The exact number of victims has never been seriously assessed.

Vietnamese authorities two years ago said anywhere between hundreds of thousands and two million people were affected. Now, Hanoi says it has approximately four million victims of Agent Orange, now including third generation victims.

Since the end of their brutal war in 1975, Hanoi and Washington have managed to resolve most of the issues that divided them and most of their disputes are economic.

But the painful question of dealing with the victims of defoliants used by the US military is yet to be answered.

"Agent Orange victims in Vietnam had no way out but filing the lawsuit," Nhan told AFP.

"We have repeatedly suggested the US to solve the consequences of war by cooperation and humanitarian activities but they refused our goodwill."

The lawsuit, filed by VAVA on behalf of millions of Vietnamese in the US Federal Court in Brooklyn, New York, is seeking compensatory and punitive damages from the 37 chemical companies that produced the agent which contains highly toxic dioxins.

The defendants, including subsidiaries of New York-listed giants Dow Chemical, Monsanto and Occidental Petroleum, are accused of complicity in war crimes and crimes against humanity, among other charges.

"The US side must understand its responsibility. Those chemical companies had the right to refuse to produce this most dangerous toxic known to human beings, but they didn't as they received great profits," Nhan said.

Late last month, the US Justice Department asked federal judge Jack Weinstein to throw out the lawsuit, arguing it should be dismissed on procedural grounds.

The move, of course, was not welcome in Vietnam.

"Why don't they come here to see with their own eyes children who are suffering from deformities," said a motorbike taxi driver in Hanoi as he was reading news about the suit.

"We must win, and we will win. Surely," he said.

The case also has an echo in the international community. A two-day international conference focusing on the long-term effects of the defoliant opens Friday in Paris.

Len Aldis, from the Britain-Vietnam Friendship Society which created the website which has gathered 680,000 online signatures in support, regards the US Justice Department's call as "nonsense and dangerous".

"It is clear that the (American) government is afraid. They fear the lawsuit will expose the truth," he said.

"The companies did manufacture Agent Orange, and they knew the effects it would have. As did the US government when they purchased the chemicals, and ordered their use on the people and land of Vietnam."

Even General Vo Nguyen Giap, who masterminded Vietnam's epic victory at Dien Bien Phu 51 years ago, felt he had to have his say on the matter.

"Regrettably, those who committed the crime against the Vietnamese people are trying to shirk their responsibility for their crime," wrote the 93-year-old national icon in a letter published by the state-controlled Vietnam News Agency.

"The lawsuit was not only for the own interests of Vietnamese victims but also for the legitimate interests of victims in other countries, including those in the US," Giap said.

In 1984, in a class action settlement with no admission of liability, the manufacturers agreed to pay 180 million dollars to US war veterans who died or became ill after exposure to Agent Orange or other defoliants.

"We haven't calculated how much compensation we would receive if we win the case, but no matter how huge it is, nothing can compensate for the victims' ordeal," Nhan said.

"Don't be afraid of us. We will not seek revenge. But we are seriously hurt. Please, help us," Nhan quoted victims as saying.

All rights reserved. � 2005 Agence France-Presse. Sections of the information displayed on this page (dispatches, photographs, logos) are protected by intellectual property rights owned by Agence France-Presse. As a consequence, you may not copy, reproduce, modify, transmit, publish, display or in any way commercially exploit any of the content of this section without the prior written consent of Agence France-Presse.